The present invention relates to an improved spin finish for synthetic fiber.
Upon emerging from a spinneret, many synthetic fibers require the application of a spin finish in order to further process the spun yarn. Because a spin finish may be present in a minimal layer on fiber, the spin finish acts as an interface between the fiber and the metallic surfaces such as guides and rollers which contact the fiber during such processing as drawing or relaxing.
Spin finishes comprising polyalkylene glycols with molecular weights of 300 to 1,000 are taught by commonly assigned U.S. Pat. Nos. 3,940,544; 4,019,990; and 4,108,781. See also U.S. Pat. No. 4,351,738.
U.S. Pat. No. 4,340,382 teaches a spin finish comprising polyalkylene glycol which is a block copolymer. Unfortunately, spin finishes comprising polyalkylene glycol block copolymers may form deposits on the metallic surfaces which they contact during manufacturing.
Spin finishes comprising polyalkylene glycols with molecular weights of greater than 1,000 are taught by U.S. Pat. Nos. 4,351,738; 4,552,671; and 5,507,989. Unfortunately, spin finishes comprising these higher molecular weight polyalkylene glycols also may form deposits on the metallic surfaces which they contact during manufacturing.
U.S. Pat. No. 4,442,249 teaches a spin finish comprising an ethylene oxide/propylene oxide block copolymer with a molecular weight greater than 1,000 and a lubricant of an alkyl ester or dialkyl ester or polyalkyl ester of tri- to hexaethylene glycol. Unfortunately, spin finishes comprising these block copolymers also may form deposits on the metallic surfaces which they contact during manufacturing.
Commonly assigned U.S. Pat. Nos. 3,681,244; 3,781,202; 4,348,517; 4,351,738; and 4,371,658 teach the use of polyoxyethylene castor oil in spin finishes.
A spin finish which is non-depositing and stable is needed in the art.
We have developed a spin finish which responds to the foregoing need in the art. The present spin finish composition comprises at least about 10 percent by weight based on the spin finish composition of components (a) and (b) having the formula
R1xe2x80x94(CO)xxe2x80x94Oxe2x80x94(CH(R2)xe2x80x94CH2xe2x80x94O)yxe2x80x94(CO)zxe2x80x94R3
wherein each of R1 and R3 is selected from the group consisting of hydrogen or an alkyl group having from one to 22 carbon atoms or an alkylene hydroxy group having from one to 22 carbon atoms,
x is zero or one,
R2 may vary within component (a) or component (b) and is selected from the group consisting of hydrogen or an alkyl group having from one to four carbon atoms,
y is zero, or from one to 25, and
z is zero or one,
in component (a), x and z are equal to zero and the average molecular weight of component (a) is less than or equal to 1,900 and if R2 varies, component (a) is a random copolymer; and
in component (b), at least x or z is equal to one or component (b) is a complex polyoxyethylene glyceride-containing compound having greater than 10 polyoxyethylene units; and
up to five percent by weight based on the spin finish composition of component (c) of an alkoxylated silicone.
The present invention is advantageous because the spin finish is substantially non-depositing and stable.
Other advantages of the present invention will be apparent from the following description and attached claims.